i want to show a new admin menu tab which will pull information from a certain category, i.e products.
I do not want to use custom Post types because i want to be able to change themes with out any modification to theme files, so please do not recommend that.
using wordpress function add_menu_page() i can add a new tab, but how to show new post page and existing posts of that category, exactly like custom post type.
thanks
Did you try the Menus?
If I'm not mistaken, what you want to do is to create a menu tab that can fetch the posts from a certain category
Create a post with your category
In your dashboard go to the Appearance > Menus Name your Menu, after creating your New Menu You can select what you want to add on that Menu by checking it and clicking Add Menu, the Categories are on the bottom part.
You should try to create your custom post types as part of a plugin anyway, as that's what WordPress recommends:
https://codex.wordpress.org/Post_Types#A_word_about_custom_post_types_as_a_plugin
That way you can them with any theme.
